Chinese Mitten Crab from Dongping Lake

Chinese Mitten Crab from Dongping Lake

　　The crabs from Dongping Lake, scientifically known as "Chinese Mitten Crab" and commonly referred to as "lake crab" or "hairy crab," are farmed in lakeside towns such as Shanglaozhuang, Yanshan, and Laohu Town. The total aquaculture water area exceeds 10,000 mu, including 5,000 mu of netted enclosures in the lake, 4,000 mu of ponds outside the lake, and 1,000 mu of rice paddies, with an annual total output of about 300,000 kilograms. Shanglaozhuang Township has the largest area and highest yield of both pond and rice paddy crab farming, accounting for about half of the county’s total crab production.

　　The Chinese Mitten Crab belongs to the family Varunidae and is a type of hairy crab. It has five pairs of walking legs; the first pair is columnar in shape with pincer-like tips called chelae. The chelae are the strongest of the five pairs and are densely covered with hair, hence the name "hairy crab." The walking legs are used for crawling, swimming, and catching food. However, because the width of its cephalothorax is greater than its length, and the legs extend on either side of the body with downward-curved joints of unequal length, the crab can only move by anchoring one side while pushing off with the other, resulting in a diagonal forward motion. This has earned it the playful nickname "crab that walks sideways."

　　The Chinese Mitten Crab typically lives and grows in freshwater but migrates to brackish coastal shallows near river mouths during the breeding season to spawn. The newly hatched larvae undergo four to six molts before becoming juvenile crabs, which then return to rivers and lakes to grow. Before the 1950s, Dongping Lake was connected to the Yellow River, and large numbers of river crabs entered the lake each year, resulting in abundant yields. In the 1960s, the construction of a dam at the lake-river junction blocked the crabs’ migration route, nearly wiping out the lake crab population. In 1975, the local fisheries department introduced 360 kilograms of crab seedlings from Chongming Island in Shanghai and successfully trialed their cultivation in the lake. By October 1976, a large number of mature crabs began migrating, yielding a catch of 200,000 kilograms that year. In 1979, crabs were so plentiful around Dongping Lake that it resembled a lantern market, with over 1 million kilograms harvested. Trial farming showed that due to the lake’s excellent water quality and abundant food supply, every kilogram of crab seedlings could produce one ton of mature crabs—higher than yields on Chongming Island—and with superior taste. Since the 1990s, crab farming areas around the lake have expanded year by year, with production soaring. Products are sold across the country and have entered international markets, earning recognition as a premium green food. As a result, there’s a saying in the crab market: "Chongming Island in the south, Dongping Lake in the north."

　　Crabs from Dongping Lake are large in size (male crabs weigh around 6 liang or 300 grams each, female crabs about 3 liang or 150 grams), rich in roe, full of yellow meat, bright in color, and delicious in flavor. They have long been featured in gourmet dishes. The underside of the crab is commonly called the "abdomen" and is used for carrying eggs. Female crabs have a round abdomen, known as "round belly," while males have a triangular one, called "pointed belly." In southern China, there’s a saying: “July for pointed-bellied males, August for round-bellied females,” meaning July is the best time for fat, pointed-bellied male crabs, while August is ideal for fat, round-bellied females. Due to climate and environmental factors, Dongping Lake crabs are generally in season during August and September. This period coincides with crisp autumn weather, blooming golden chrysanthemums, and the peak tourist season at Dongping Lake. After enjoying the scenic lake and mountain views, visitors can savor chrysanthemum-season crabs, rich in roe and yellow meat, adding extra delight to their trip.

　　Besides being a delicacy, lake crabs have multiple uses—for example, their shells can be processed to extract chitin, which is widely used in textiles, dyeing, synthetic fibers, papermaking, plastics, and medicine.